The present invention relates to connectors for use in medical flow lines for blood transfer, intravenous medication and nutritional supply, and the like. In accord with usual medical terminology, the connector may be referred to as having distal and proximal ends respectively designating the ends of the connector which are ordinarily positioned nearest and farthest from the patient.
U.S. Pat. No. 5,273,533 issued Dec. 28, 1993 and U.S. Pat. No. 5,306,243 issued Apr. 26, 1994 to Bonaldo each disclose a medical connector having an elastomeric element in the form of a septum or fluid barrier disposed in a two part plastic housing. The septum is pierced by a pointed cannula in the connector when making the connection to the fluid flowline. Disconnection of the flow line allows the elastomer to re-seal the connector. Repeated usage of such connectors may cause the connector to leak or become contaminated with particulate material such as particles which may detach from the septum. Repeated disconnection of the flowlines from the connector and decontamination of the connector and flowlines, as by swabbing with alcohol, is at least a daily occurrence. Thus, these connectors may be actuated or cycled many times and must remain leak free and reliably avoid introduction of contaminants such as cotton fibers from swabs used to clean the connectors into the flowline.
Medical connectors which use resilient flow barriers which are repeatedly pierced during use of the connector become more subject to fluid leakage with increased actuation cycles, particularly if connected in an infusion pump line which may subject the connector to pressures as high as 27 psi. U.S. Pat. No. 5,947,954 issued Sep. 7, 1999 to Bonaldo, the teachings of which are incorporated herein by reference, discloses a needleless connector which is addressed to the above concerns which includes attached relatively rotatable male and female Luer connector parts with an eccentrically positioned flow passageway at the inner end of the female Luer connector. A removable plastic plug, permanently attached to the connector by a strap, and which fulfills the function of a cleansing swab for the female Luer connector is also provided as an optional feature.
Although the removable plug when properly used closes the female Luer when the female Luer is not connected to a flowline, it has been found in practice that additional manipulation of the plug is required for proper use and that the plug can inadvertently become dislodged leaving the female Luer open to atmosphere and possible contamination. Accordingly, a more reliable and easy to use swabbable stopper for the female Luer part of the connector has been developed which always remains in proper position yet which also permits easy connection/disconnection of the male Luer end of a flowline to/from the connector valve is disclosed and claimed in a more recent U.S. Pat. No. 6,364,869 issued Apr. 2, 2002 to Bonaldo, the full teachings of which are also incorporated herein by reference. This stopper has an exterior end which essentially completely closes the otherwise open end of the female Luer when the connector is not in use to prevent introduction of fibers or other contaminants into the flow path in the connector. However, since fluid flow takes place along the outside of a stopper guide post mounted in the connector, it has been found that fluid may remain in the annular space between the post and inside wall of the swabbable stopper.
There remains a need to provide a further improved medical connector which includes a female Luer end having a swabbable elastomeric stopper which still further reduces the likelihood of contaminant entry to the fluid flow path. Also, there remains a need for a connector which has readily observable indicators thereon to enable the user to determine if the relatively rotatable parts of the connector are positioned to place the connector in the open or closed position.
Medical connectors are provided in fluid flowlines which ordinarily deliver blood, plasma or medication to a patient by gravity flow or with the assistance of an infusion pump. Often, when the medication in the container is exhausted, a pressure condition can be created by the patient's vascular pressure which results in retrograde flow of medication back from the patient to the flowline. Also, since it is frequently necessary to interrupt the flow of fluid to the patient as when changing the supplies of blood, plasma or medication or when it is necessary to draw blood from the patient, positive fluid pressure in the flowline which is ordinarily present is absent and undesired retrograde flow of blood from the patient into the flowline may take place. Retrograde flow is ordinarily prevented by inserting a separate one-way valve such as a duckbill valve, sometimes referred to as a heparin lock, in the flow line. Duckbill valves remain open under positive line pressure during delivery of flow to the patient but automatically close to prevent retrograde flow of medication and blood when delivery pressure is absent. The one-way valves used in the prior art, although effective for preventing retrograde flow, must be separately installed in the flowline and prevent the drawing of blood unless the one-way valve is removed from the flowline. Further improvements in medical connectors such as the connectors referred to in the above Bonaldo patents are desired to provide connectors having a self contained means of preventing retrograde flow of medication and blood and which permit the drawing of blood when desired.